A conventional light-emitting device provided with an LED is disclosed, for example, in Patent Document 1 identified below. In this light-emitting device, an LED is embedded in a molding (reflector) which has formed thereon a first reflective face which is increasingly wide open from the bottom face of the molding upward and a second reflective face which is contiguous with the first reflective face and is increasingly wide open further upward, and the LED is sealed in resin from around. The inclination angle of the second reflective face is so set as to be larger than 0° but smaller than the critical angle at the interface between the resin and the layer of air. With the inclination angle of the second reflective face so set, more of the light that is totally reflected on the interface, is then totally reflected on the second reflective face, and is then incident on the interface again can be extracted, achieving improved light extraction efficiency.
However, in the structure according to Patent Document 1, the first reflective face (inner wall) of the molding is located close beside the LED, and the light emergent from the LED is incident on the inner wall directly (across a short distance). This may discolor the inner wall and shorten the lifetime of the package. In particular, in a case where a high-luminance blue LED is used and the molding is formed of white resin with high reflectance, the white resin turns increasingly yellow, which significantly lowers the light output of the package and significantly shortens the lifetime of the package.
As an improvement, in the light-emitting device according to Patent Document 2 identified below, a metal lead frame is bent to form a recess, which is surrounded by a reflector, and an LED is arranged on the bottom face of the recess and is sealed in transparent resin. In this structure, the light emergent from the LED is reflected on the side face of the recess, and this reduces the light that is directly incident on the inner wall of the reflector. It is thus possible to alleviate discoloration of the inner wall and to prolong the lifetime of the package.
Patent Document 2 also discloses a structure in which an LED is arranged on one of a plurality of metal lead frames arranged apart from one another and the electrodes of different polarities of the LED are electrically connected to different ones of the metal lead frames via bonding wires respectively, wherein the metal lead frames each have a fin portion formed integrally therewith. The fin portion is provided at opposite sides of a bottom portion of each metal lead frame, with an inclination relative to the bottom portion, so as to form reflective faces. Also with this structure where the light from the LED arranged in the bottom portion of the metal lead frame is reflected on the fin portion, it is possible to reduce the amount of light that is directly incident on the inner wall of the reflector and to alleviate discoloration of the inner wall.